class Singleton{
    private volatile static Singleton instance ;
    public static Singleton getInstance(){
        if(instance == null){
            synchronized(Singleton.class){
                if(instance == null){
              instance = new Singleton();
                }
            }
        }
       return instance ;
    }
    private Singleton(){};
}



public class Test1 {
    public static void main(String[] args) {


    }
}
